The objective of the current work is the design and development of an acquisition, processing and storage data system for monitoring the condition of power transformers. Using techniques for data storage (Data Warehouse) and virtual instruments, a measuring system was created in four 40 MVA transformers. The application that handles the prediction models was provided with an abstraction of the sensors, which the authors have named Virtual Acquisition Cards. Compared with available commercial software the acquisition system developed in this work has the advantage of being easily reconfigurable. The subsystems designed can be easily modified to monitor the estate of any other equipment that needs to measure variables using sensors